The present invention relates to a living body discriminating apparatus.
A person check is performed by extracting a person's feature quantities by using fingerprint, voiceprint, face image, etc. These data are peculiar to every person, and the recognition rate is extremely increased by dealing with increased resolution digital data. However, there is a possibility that data which is not obtained from a person, i.e., forged data, may be erroneously recognized in case of checking artificial digital data. To solve this problem, such means as one in which a check as to whether the checked data of living body is performed by also taking daily life data, or one in which oral questions concerning the pertinent person are made when inputting data. A method as the former means is disclosed in, for instance, Japanese Patent Laid-Open Publication No. 4-241680. In this method, when inputting fingerprint, various excitements are given to the finger. If the finger is of a living body, it responds to the excitements sensed by it. Other methods as the former means are disclosed in Japanese Patent Laid-Open Patent Application No. 6-187430. These methods are to check the pulsation, blood pressure, etc. by using pressure sensor and to detect infrared rays emitted from the finger by using an infrared sensor. A method as the latter means is disclosed in Japanese Patent Laid-Open Publication No. 1-233556. In this method, it is verified that the subject person is living, i.e., exists, by giving him or her instructions.
However, in the method disclosed in Japanese Patent Laid-Open Publication No. 4-241680, in which when inputting the fingerprint various excitements are given to the finger and, if the finger is of a living body, it responds to the excitements sensed by it, the responding means is left to the will of the subject person. Therefore, the subject of the fingerprint check need not be the pertinent person, and this means that forging is possible. In the methods disclosed in Japanese Patent Laid-Open Application No. 6-187430, i.e., one in which the pulsation, blood pressure, etc. are checked by using a pressure sensor, and one in which infrared rays emitted from finger are detected by using an infrared sensor, also have problems. In the case of using the pressure sensor, signals involved are simple. Therefore, even in case of any thing other than living body it is possible to provide pulsation data or blood pressure data to the pressure sensor by applying pressure thereto. In the case of the infrared ray detection method, forging is also possible by mounting, for instance, an infrared radiator on the replica finger. In the method of verifying the subject person by giving him or her instructions, the living body is known as such in the stage of the oral questions. The method, therefore, is an auxiliary means for checking the pertinent person.